The present invention relates to a transport roller assembly adapted to be releaseably fixed on a supporting shaft, and which is adapted for use as a yarn delivery roller in a yarn false twisting machine or the like.
Yarn false twisting machines typically comprise a number of twisting stations wherein a running yarn is subjected to simultaneous twisting, heat setting, cooling, and untwisting operations, and which results in the twist being permanently set in the yarn. The twisting apparatus of each station commonly comprises twist imparting members having cooperating friction surfaces, such as a pair of rotating discs as described in U.S. Pat. No. 4,339,915. Also, a number of yarn feed rollers are commonly associated with the twist imparting apparatus, and typically, each of the feed rollers comprises a one piece steel or aluminum roller which is fixed to a drive shaft by set screws. The yarn is positioned to engage the outer drive surface of each roller, and upon rotation of the drive shaft and roller, the yarn is advanced at a speed on the order of about 900 meters per minute.
By reason of their high rotational speed, yarn delivery rollers of the described type are susceptible to damage, such as when a foreign object contacts and chips the surface of the rotating roller. Thus the rollers must be frequently replaced, and with existing one piece rollers, the entire roller must be removed and replaced. This is not only a time consuming operation, but in addition, the rollers are quite expensive.
It is accordingly an object of the present invention to provide a transport roller assembly which is adapted for use as the yarn delivery roller on a false twisting machine, and which reduces the time and expense of replacing the roller upon its surface being damaged.
It is a more particular object of the present invention to provide a transport roller assembly which is composed of two components, and wherein only the outer component is replaced upon its surface being damaged, and wherein a single mounting operation acts to both secure the two components together and secure the assembly to its supporting shaft.